Why no improved AR bolts?

[H2O MAN]

Smith Enterprise, Inc. now has complete BCGs for the AR and M16.
They even have a hard chromed version... available from Brownells and SEI.

 

[nhm16]

FWIW, AR Performance (of high quality 6.8 SPC uppers fame) is also selling what they call superbolts, machined from 9310 alloy. He did talk about the design a bit on 68forums but I can't remember offhand the exact improvements.

 

[wickedsprint]

I wonder if the mil-spec bolts have to be as strong as they are due to most soldiers letting them slam forward on empty chambers every time they use a clearing barrel..most civilian owners don't do this to their weapons.

 

[Nicky Santoro]

Why no improved AR bolts?

I never had a bolt failure with the M16 when in the Army nor any time therefter with an AR15.
FWIW
YMMV

 

[mp5a3]

So it's bad to dry cycle a weapon ?

 

[Bartholomew Roberts]

So it's bad to dry cycle a weapon ?

No. You can dry cycle/dry fire and AR15 all you like.

 

[everallm]

There HAVE been incremental improvements in the bolt of the AR-15/M-16 since issuance

In no particular order the first 3 that come to mind

Changes in the metallurgy of the bolt
Changes to the geometry of the lugs on the bolt face
Changes to the physical shape of the lugs

All of these changes have been within the overall design not changing much so as to allow backwards compatibility.

To actually "improve" the bolt then a wholesale review and redesign would break the compatibility requirement.

For example is the high number, multi-lug "daisy head" pattern best or would a different form be "better". As an example the AK or XCR bolt head which has 3 large lugs.

Example below of bolt from the left to right an XCR, AK, AR-10, AA Grendel, AR-15, Kel Tec PLR

 

[Evil Monkey]

For example is the high number, multi-lug "daisy head" pattern best or would a different form be "better". As an example the AK or XCR bolt head which has 3 large lugs.

Don't forget that some 7-lug bolts like the Steyr AUG bolt have longer lugs to improve shear strength. It's not always about the number of lugs.

 

[DBR]

One of the simplest things an owner can do to improve bolt longevity is polish the sharp edges off of the cam pin hole in the bolt body.

The sharp edge on most bolts I have seen is an invitation to a crack. It's called a "stress riser". Irregularities in this edge can make the stresses on the bolt act like they a a lot higher than they actually are.

Don't attack it with a grinder. I use a Craytex rubber point and just break the edge to clean it up.